* I am going to the store. == now
* I will go to the store and then to the party. == now
* After I wake up, I willl go to the store and then to the party. == later
* Next weekend, I will go to the store and then to the party." == next weekend(sorta planning.)
* What will you do next weekend?" -- "I'll go to the store and then to the party." == next weekend.

* I will sleep after I take a shower
* I am gong to sleep (really, right now i'm crawling into bed and my eyes are closing .....)
or "I'm going to sleep" (turn off the computer and crawl into bed)

I think it's simply that "out of order" is used mainly for public facilities. An escalator, a public phone, an elevator, a fire escape are out of order. A private phone, a car, the microwave oven in your kitchen are not "out of order".